Process of manufacturing artificial-silk threads from viscose



Patented Oct. 20, 1925.

ZUNITIED" sra t sazeyji TESV PATENT OFFICE. v

rsrnoun oc'rAvnEmLn mus; or 'rm'arz n, BELGIUM, ASSIGNOR-Td FABRI'QUE DE sorn anrrrrorsmrn DE munrzn, soornrn axons ME, or BRUSSELS, BELGIUM.

rations-s F MANUFAGTURINGARTIFIQIIAIL-SILK THREADS FROM VISCOSE.-.

No Drawing."

To all whom it may concern:

Be it known that I5, Ismoun Oo'rAvE EMILE LAMS, a Subject of the Kingof the Belgians,

' residingat'Tubize, in the Kingdom of Belgium, have invented certain new and useful Improvements in the Process of Manufacturing Artificial-Silk Threads'fro'm Viscose, oftwhich the following is a specification.

My invention'relates to a process of'manufacturi'ng artificial silk threads from viscose. One object of my invention is to produce a thread ofoellulose Xanthatewhich will be more extensible than the threads hitherto obtained so that it can be drawn out into a very thin thread before being precipitated into a thread of cellulose hydrate. a-

i further object of my invention is'to improve 1 the brilliancy andsuppleness of'the thread thus obtained.

l/Vith these objects in view my invention consists in making use of a special coagulating bath composed of ammonium formate at the minimum required concentration to neutralize the free soda which is present in the viscose solution and of sodium formats at the minimum required concentration to secure coagulation.

Experiences have shown that the follow-- easily drawn out into a i ery thin thread and Application filed January 18, 1923. Serial No. 613,541. I

which possess a coeilicient of drawing of 98%,v that is tosay that a length of -1 1n.

of the elementary thread or filaments issu-I ing from the spinning orifice can be drawn or stretched so as to present an increase of length of 98 cm. before breaking.

In carrying my invention into practice the viscose solution is projected as usually through fine orifices intothe above stated coagulating bath; the thread is drawn out according tothe well known method a-ndis finally precipitated in the form of a thread of cellulose hydrate by. any well known method for instance. by aid of an acid solution of weak concentration. it is however advisable to make this decomposition rapidly so as to avoid any possible disturbance in working resulting from the sticking or gluing of the threads to-each other.

YVhat I claim is:

1. In the process of manufacturing artificial silk threads from viscose, the steps which comprise subjecting viscose threads to the action of an aqueous solution cmitaining 13 to 15% of an'mionium formate and 13 to 18%of sodium iorrnate, drawing the threads while so coagulated, and then converting them into cellulose hydrate.

2. As. a new composition of matter, an aqueous solution of 13 to'15% of ammonium formate and 13 to 18% of sodium formate, the said composition having coagulating proerties whereby viscose threads are converted threads.

In testimony whereof I have affixed my signature.

into extensible cellulose Xanthate 

